gms | German Medical Science

Objective: Skull base chordomas are locally invasive tumors that can extend into multiple skull base compartments. Microsurgical resection of skull base chordomas is challenging due to tumor location and its invasive nature.

Methods: Ten patients suffering from skull base chordomas were operated in our institution between 2010 and 2016. The patients were operated under intraoperative MRI control (Magnetom Espree Siemens AG Medical Solution, software NUMARIS/4 version syngo MR B17). Six patients had a variable intradural extension of the tumor. In four patients, the tumor encroached on the brainstem with its intradural component. In four patients, the tumor had lateral extension across the petroclival fissure with variable extension into the cavernous sinus. In five patients, the target components and volume was achieved and confirmed in the first MRI control. In three patients, the target volume was achieved and confirmed in the second MRI control. The target was reached in 2 patients after 3 MRI controls.

Results: Total tumor resection was achieved in 5 patients. The mean volume of the tumors was 18.86 cm3, SD=12.43 and the mean volume of the residual tumor was 4.37, SD= 8.17. The mean volume of the resected tumor was 14.47 cm3, SD=5.02cm3. The KPS improved in 6 patients and was unchanged in 4 patients. The improvement of the KPS was significantly correlated to the resection of the intradural parts and decompression of the brainstem. The number of the intraoperative MRI controls was also significantly correlated to the presence of intradural extension.

Conclusion: The intraoperative MRI is a helpful tool even in experienced hand to maximize the degree of resection of skull base chordomas, especially for tumors with intradural extension and when patient positioning possible for intraoperative MRI. There were no technique-related complications.